On Apr 20, 2012, at 3:30 PM, Chuck Lever wrote:
>
> On Apr 20, 2012, at 3:21 PM, Weston Andros Adamson wrote:
>
>> nfs4_path() was parsing the path component by splitting on the first colon.
>> This is wrong when an IPv6 address is used to mount a server.
>>
>> For example, having mounted 'fc00::10:/export', nfs4_path() returned
>> ':10:/export'. This causes referrals (using IPv4 or IPv6 addresses) to fail
>> in nfs4_validate_fspath().
>>
>> Parsing the path component by using the *last* colon works with
>> IPv6 as well as IPv4 addrs.
>
> These ad hoc fixes give me the willies.
>
> During a referral, how is the server name and export path getting recombined? In fs_locations data, these are separate. In the forward mount path, IPv6 addresses are escaped via square brackets.
Again, the string that needs to be split into (server, path) is not the fs_locations side -- those are already separated. What's not separated is the result of nfs_path().
> (Having not looked at this code in years), is there some way we can keep the server name and path separate here so we don't have to reparse?
nfs_path() walks up the dentry tree until it hits the root dentry of the nfs mount, then it uses dentry.d_fsdata to get the "dev_name" of the mountpoint (<server>:<path>) to make <server>:<rootpath + path to the dentry>.
The problem I'm having is how we can generate the string "<rootpath of parent mount>/<path-to-current-dentry>" without adding [] escaping to dev_name, or adding another variable to dentry (not likely!).
-dros
>
>> Signed-off-by: Weston Andros Adamson <dros@xxxxxxxxxx>
>> ---
>> fs/nfs/nfs4namespace.c | 2 +-
>> 1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
>> index 9c8eca3..dd3dd30 100644
>> --- a/fs/nfs/nfs4namespace.c
>> +++ b/fs/nfs/nfs4namespace.c
>> @@ -59,7 +59,7 @@ static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen)
>> char *limit;
>> char *path = nfs_path(&limit, dentry, buffer, buflen);
>> if (!IS_ERR(path)) {
>> - char *colon = strchr(path, ':');
>> + char *colon = strrchr(path, ':');
>> if (colon && colon < limit)
>> path = colon + 1;
>> }
>> --
>> 1.7.4.4
>>
>> --
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